Simon Jones has pulled out of Worcestershire's LV County Championship Division Two game against Essex at Colchester on Wednesday.
Jones limped out of the last day of the drawn game against Derbyshire and director of cricket Steve Rhodes says the Welshman is still not fit.
He told BBC Hereford and Worcester: "His knee is bothering him a little bit so he won't play."
The seam bowler was forced to withdraw from the England Lions squad for the two one-day matches against South Africa last week because of injury.
He has suffered with a series of injuries over the past three years and was hoping to impress the selectors before they consider their final squad for the Champions Trophy and the tour to India later this year.
Jones has claimed 52 championship wickets in only nine matches since moving to Worcestershire this season.
